Comment #42 on issue 2783 by [email protected]: wrong placement of timesignature
http://code.google.com/p/lilypond/issues/detail?id=2783
The visual changes are all to the position of the time signature on non-standard lines. I'd go with the view that says that, if you're placing your staff lines in odd places, it's your responsibility to put the time signature in the right place. So these look OK to me.
